Effects of charge impurities and laser energy on Raman spectra of graphene.
The position and width of the Raman G-line was analyzed for unintentionally doped single-layered graphene samples. Results indicate a significant heating of the monolayer by the laser beam. Moreover, a weak additional component was resolved in the G-band. The position of the line is independent of the level of doping of the sample. We conclude that this new component is due to the phonons coupled to the intraband electronic transitions.
Hulman
Martin
M
Danubia NanoTech, s.r.o., Ilkovicova 3, 812 19 Bratislava, Slovakia. hulman@danubiananotech.com
Haluska
Miroslav
M
Scalia
Giusy
G
Obergfell
Dirk
D
Roth
Siegmar
S